William versus Hardrada after an early Norman invasion

What happens if William defeats Harold early in 1066 but Harald Hardrada later invades and takes York?

William and Hardrada probably fight, with northern English support giving Hardrada a real chance and possibly drawing England into a Scandinavian political orbit.

The panel expects a direct struggle between William and Hardrada rather than an uncontested Norman conquest. Hardrada would arrive with support from northern English nobles and experience fighting Normans, while William could face both the Scandinavian force and locals angered by his occupation. The English might also wait for the two invaders to weaken each other before attacking the winner. A Hardrada victory could pull England toward a Scandinavian political orbit resembling Cnut's realm, although the panel cautions that such composite empires rarely remain stable for long. The counterfactual turns on regional allegiance and campaign sequencing as much as battlefield strength.